1 (edited by danadam 2020-11-29 04:01:33)

Topic: RME ADI-2, pulseaudio and strange internal clock change


I posted a similar topic on ASR already but so far no responses. I thought I will try here.

I have RME ADI-2 Pro FS R BE with the latest firmware, connected through USB. My pulseaudio is configured with alternate samling rate:

default-sample-format = s32le
default-sample-rate = 44100
alternate-sample-rate = 96000

so when I play 44.1 kHz file, the DAC shows internal clock "44.1" and when I play 96 kHz file, it shows "96.0". So far all fine and as expected. Now, if I open "pavucontrol" (PulseAudio Volume Control) while playing that 96 kHz file, then for some reason the DAC switches its clock to "44.1". PulseAudio still sends data with 96 kHz sampling rate, so it ends up sounding like this (internal clock in bottom right):


As per video description, first the 44.1 kHz file is played (for 2 sec), then the 96 kHz file is played and while it is playing "pavucontrol" is opened (at 0:05).

Both before and after running "pavucontrol" the alsa and pulseaudio sink parameters are the same:

]# /proc/asound/card2/pcm0p/sub0/hw_params
format: S32_LE
subformat: STD
channels: 2
rate: 96000 (96000/1)
period_size: 44100
buffer_size: 88200

]# pacmd list-sinks
  * index: 3
        name: <alsa_output.usb-RME_ADI-2_Pro__57760455__FC0F29710C736C8-00.analog-stereo>
        state: RUNNING
        sample spec: s32le 2ch 96000Hz

The system seems to be stuck in this state (i.e. alsa/pulseaudio at 96 kHz, DAC at 44.1 kHz) until I both stop the player and quit "pavucontrol".

This happens on my Debian Testing (kernel/alsa k5.9.0-1-amd64, pulseaudio 13.0) and Ubuntu 20.04 (kernel/alsa 5.4.0-51-generic, pulseaudio 13.99.1).

Also, this does not happen with other DACs (Speaka and Dragonfly).

Does anyone experience something like that with ADI-2?